The present invention relates generally to a healing component in a dental implant system and a method for making the same. More particularly, the present invention relates to the use of information markers on the exterior of a healing abutment to eliminate the need for an impression coping in the dental implant system and quicken the time required to construct permanent dental components.
The dental restoration of a partially or wholly edentulous patient with artificial dentition is typically done in two stages. In the first stage, an incision is made through the gingiva to expose the underlying bone. An artificial tooth root, usually a dental implant, is placed in the jawbone for integration. The dental implant generally includes a threaded bore to receive a retaining screw holding mating components therein. During the first stage, the gum tissue overlying the implant is sutured and heals as the osseointegration process continues.
Once the osseointegration process is complete, the second stage is initiated. Here, the gum tissue is re-opened to expose the end of the dental implant. A healing component or healing abutment is fastened to the exposed end of the dental implant to allow the gum tissue to heal therearound. Preferably, the gum tissue heals such that the aperture that remains generally approximates the size and contour of the aperture that existed around the natural tooth that is being replaced. To accomplish this, the healing abutment attached to the exposed end of the dental implant has the same general contour as the gingival portion of the natural tooth being replaced. During the typical second stage of dental restoration, the healing abutment is removed and an impression coping is fitted onto the exposed end of the implant. This allows an impression of the specific region of the patient""s mouth to be taken so that an artificial tooth is accurately constructed. Thus, in typical dental implant systems, the healing component and the impression coping are two physically separate components. Preferably, the impression coping has the same gingival dimensions as the healing component so that there is no gap between the impression coping and the wall of the gum tissue defining the aperture. Otherwise, a less than accurate impression of the condition of the patient""s mouth is taken. The impression coping may be a xe2x80x9cpick-upxe2x80x9d type impression coping or a xe2x80x9ctransferxe2x80x9d type impression coping, both known in the art. After these second stage processes, a dental laboratory creates a prosthesis to be permanently secured to the dental implant from the impression that was made.
In addition to the method that uses the impression material and mold to manually develop a prosthesis, systems exist that utilize scanning technology to assist in generating a prosthesis. A scanning device is used in one of at least three different approaches. First, a scanning device can scan the region in the patient""s mouth where the prosthesis is to be placed without the need to use impression materials or to construct a mold. Second, the impression material that is removed from the healing abutment and surrounding area is scanned to produce the permanent components. Third, a dentist can scan the stone model of the dental region that was formed from the impression material and mold.
Three basic scanning techniques exist, laser scanning, photographic imaging and mechanical sensing. Each scanning technique is used or modified for any of the above-listed approaches (a scan of the stone model, a scan of the impression material, or a scan in the mouth without using impression material) to create the prosthesis. After scanning, a laboratory can create and manufacture the permanent crown or bridge, usually using a computer aided design (xe2x80x9cCADxe2x80x9d) package.
The utilization of a CAD program, as disclosed in U.S. Pat. No. 5,338,198, (Wu), whose disclosure is incorporated by reference herein, is one method of scanning a dental region to create a three dimensional model. Preferably, after the impression is taken of the patient""s mouth, the impression material or stone model is placed on a support table defining the X-Y plane. A scanning laser light probe is directed onto the model. The laser light probe emits a pulse of laser light that is reflected by the model. A detector receives light scattered from the impact of the beam with the impression to calculate a Z-axis measurement. The model and the beam are relatively translated within the X-Y plane to gather a plurality of contact points with known location in the X-Y coordinate plane. The locations of several contact points in the Z-plane are determined by detecting reflected light. Finally, correlating data of the X-Y coordinates and the Z-direction contact points creates a digital image. Once a pass is complete, the model may be tilted to raise one side of the mold relative to the opposite vertically away from the X-Y plane. Subsequent to the model""s second scan, the model may be further rotated to allow for a more accurate reading of the model. After all scans are complete, the data may be fed into a CAD system for manipulation of this electronic data by known means.
Photographic imaging can also used to scan impression material, a stone model or to scan directly in the mouth. For example, one system takes photographs at multiple angles in one exposure to scan a dental region, create a model and manufacture a prosthetic tooth. As disclosed in U.S. Pat. No. 5,851,115, (Carlsson), whose disclosure is incorporated by reference herein, this process is generally initiated with the process of taking a stereophotograph with a camera from approximately 50 to 150 mm away from the patient""s mouth. The stereophotograph can involve a photograph of a patient""s mouth already prepared with implantation devices. Correct spatial positioning of the dental implants is obtained by marking the implant in several locations. The resulting photograph presents multiple images of the same object. The images on the photographs are scanned with a reading device that digitizes the photographs to produce a digital image of the dental region. The data from the scanner is electronically transmitted to a graphical imaging program that creates a model that is displayed to the user. After identification of the shape, position and other details of the model, the ultimate step is the transmission of the data to a computer for manufacturing.
A third scanning measure uses mechanical sensing. A mechanical contour sensing device, as disclosed in U.S. Pat. No. 5,652,709 (Andersson), whose disclosure is incorporated by reference herein, is another method used to read a dental model and produce a prosthetic tooth. The impression model is secured to a table that may rotate about its longitudinal axis as well as translate along the same axis with variable speeds. A mechanical sensing unit is placed in contact with the model at a known angle and the sensing equipment is held firmly against the surface of the model by a spring. When the model is rotated and translated, the sensing equipment can measure the changes in the contour and create an electronic representation of the data. A computer then processes the electronic representation and the data from the scanning device to create a data array. The computer then compresses the data for storage and/or transmission to the milling equipment.
The present invention provides healing abutments comprising information markers and methods of forming the same. During the second stage of dental restoration, a healing abutment is non-rotationally fastened to the implant with an abutment-attaching bolt. According to the invention, the information markers eliminate the need for an impression coping within the implant system. Further, such a system eliminates the need to remove the healing abutment until the permanent components are ready to be installed in the patient""s mouth.
Information markers located on at least one surface of the healing abutments of the present invention allow the dentist to determine the size of the healing abutment and the size and orientation of the implant seated below the healing abutment. Specifically, the information markers, when used in combination, permit identification of the healing abutment height, healing abutment diameter, dimensions of the attached implant seating surface, and implant hex orientation. A common type of dental implant has a hexagonal post or boss (commonly called a xe2x80x9chexxe2x80x9d) on its gingival end that is adapted to mate with a cooperating socket on a restoration component.
It is contemplated in accordance with one embodiment of the present invention that these information markers may be disposed on the top and/or the sides of the healing abutment. It is also contemplated in accordance with one embodiment of the present invention that the information markers may extend outward (positive) from or inward (negative) towards the healing abutment. It is also contemplated that a healing abutment of one embodiment of the present invention may comprise a combination of positive and negative information markers. It is further contemplated that the top or side surface of the healing abutment can be etched or defined with a polygonal, numerical, or line marking to indicate height, location and orientation of the underlying hex, abutment and/or implant.
In one embodiment of the present invention, the positive or negative information markers correspond to the height of the abutment to be captured in an impression or subsequent scan. For example, a 6-mm tall healing abutment could possess 6 information markers on the top or side surface of the healing abutment. A 4-mm tall healing abutment could possess 4 information markers and a 2-mm tall healing abutment may possess 2 information markers. This marking system could be altered to decrease the quantity of information markers required on the top or side surface of the healing abutment. For example, it is contemplated in accordance with the present invention that the use of 3 information markers on the top or side surface could represent a 6-mm tall healing abutment, 2 information markers to indicate a 4 mm tall abutment, and 1 marker to indicate a 2-mm tall abutment.
It is also contemplated that the healing abutments of the present invention can be manufactured in sets of healing abutments, each set having healing abutments of the same diameter but different healing abutment heights. Different sets of healing abutments would have healing abutments with different diameters. For example, a first set of healing abutments may contain 3 healing abutments, one abutment of 2 mm, 4 mm, and 6 mm height, respectively, and each with a diameter of 4 mm. A second set of healing abutments would also have abutments with heights of 2 mm, 4 mm, and 6 mm, but these abutments would have a diameter of 5 mm. Information markers would distinguish not only between the first and second set of healing abutments, but also between the three healing abutments within each set.
Several different types of information markers are used on the healing abutments of the present invention to indicate and correspond to various characteristics of the implant and/or the healing abutment. The information markers are placed on the healing abutment in order to identify characteristics such as the diameter of the healing abutment, the diameter of the implant""s seating surface (and, consequently, the size of the hex), the height of the healing abutment, and the orientation of the hex (and, thus, the angle of the underlying implant).
Machined notches are one example of information markers. The quantity of notches and the location on the top and/or side surface of the healing implant can identify, for example, the height and diameter of the healing abutment. A numeral may also appear on the top or side surface of the healing implant as an information marker. For example, a xe2x80x9c4xe2x80x9d might indicate a 4 mm tall healing abutment or a 4 mm diameter healing abutment. A barcode can also be disposed on the top or side surface of the healing abutment of the present invention. This barcode is pre-coded with most of the dimensional variables of a particular healing abutment. The laboratory or dentist would only then have to use a barcode reader and display to obtain all of the required information about the healing abutment. If a dentist utilizes a barcode reader to obtain this information, it would only be necessary to identify the angular orientation of the implant hex by information markers on the top or side surface of the healing abutment.
The top and/or side surface of the healing abutment could also contain recessed dimples or raised pimples. These types of information markers are used to identify, for example, the height of the healing abutment and/or the orientation of the hex. An etched or machined polygon (e.g., triangle, pentagon, hexagon, quadrilateral, etc.) is used to signify the location or existence of several of the healing abutment and/or implant variables. For example, the location of an etched hexagon on the surface of a healing abutment of the present invention can indicate, for example, the exact orientation of the underlying hex. Another type of information marker to allow indication of healing abutment or implant variables is an etched or raised line on the top and/or side surfaces of the healing implant. The number and location of these lines can indicate, for example, the height of the healing implant or the diameter of the implant or healing abutment. It is contemplated in accordance with the present invention that the different types of information markers can be used, either alone or in combination, to help the dentist and the laboratory determine the different variables of the healing abutment and the implant.
An impression of the mouth is taken with the healing abutment mounted on the implant. The impression process creates a xe2x80x9cnegativexe2x80x9d image of the information markers in the impression material that change the physical shape of the top or side surface. Of course, the etched markers would not create a xe2x80x9cnegativexe2x80x9d image. A corresponding mold is created from the impression. This mold or a stone model created from the mold can then be scanned. A computer program is able to create a three-dimensional perspective of the relevant jaw section of the patient, including the implant and abutment. Due to the information markers on the surface of the healing abutment now present in the mold, the computer program is able to accurately analyze and produce the appropriate dimensions of the aperture in the gingiva and the orientation of the underlying hexagonal boss of the implant so that a clinician can instruct a milling machine to produce the permanent components.
In an alternative embodiment, the scanner simply takes the necessary information directly from the mouth of a patient without the need for impression material whatsoever. The information markers of the healing abutment provide the required information of the gingival aperture and the orientation of the underlying hexagonal boss on the implant. If a laser or photographic scanning system is used, the etched markers are identified just as easily as the markers that change the physical shape of the healing abutment.
This system allows the dentist to produce the permanent components more quickly because the healing abutment does not have to be removed in order to produce the permanent dental components. In other words, the second step of taking an impression with an impression coping is eliminated. The dentist also does not have to confront the difficulties of gingival closure that appear when a healing implant is removed. Finally, the patient is not forced to endure the somewhat painful procedure of healing abutment removal. With the procedure of the present invention, the removal of the healing abutment can occur during the same surgery as the installation of the permanent components.
In a further alternative embodiment, it is contemplated in accordance with the present invention that an impression coping may possess information markers as described above and replace the standard healing abutment during second stage dental restoration surgery. The impression coping and surrounding environment are scanned directly in the mouth. An impression could also be formed and a stone model produced from the impression. This stone model is scanned to create the permanent prosthesis, using one of the scanning techniques described above.